Arrange orange slices in single layers on 2 wire racks. Bake for 1 hour 40 minutes or until orange starts to dry out but still retains colour. Reduce oven to 70°C (50°C fan-forced) and bake for a further 20 minutes or until orange is completely dry and allow to cool.
Temper your chocolate over a double boiler (a heat proof bowl over a simmering saucepan of water) or heat chocolate in microwave in 15-30 second increments at 50% power until melted. Stir to combine the melted chocolate with the unmelted chocolate until smooth.
Dip half of orange slice into chocolate and place on baking paper until set, then transfer to an airtight container until ready to serve.
